Move the URLs into the candidates application urls.py
Use better constituency view URLs

We're moving towards consistently using MapIt area IDs to refer to
constituencies - this change also makes the constituency URLs look
better (e.g. with no uppercase or percent-encoded spaces)
Switch the standing / not standing buttons to use the MapIt Area ID

This is a series of changes to make the way we refer to constituencies
and candidate lists consistent, and all use the MapIt Area ID.
The sleep doesn't seem to make a difference
Also print out the membership count from the PUT response
Switch the new person form to use the MapIt Area ID

This is a series of changes to make the way we refer to constituencies
and candidate lists consistent, and all use the MapIt Area ID.
Some people may have memberships with no 'classification'
Add a view for autocompleting party names

This returns results roughly in order of the number of candidates each
party fielded in 2010.
Add the party autocomplete URL to the context where needed
Add a comment introducing some hide / reveal JS logic
Add autocompletion of party names with jQuery UI
Add a horrible hacky sleep to workaround a timing-related bug

This bug is described further in:

  https://github.com/mysociety/popit/issues/631

Essentially a GET for a person immediately after a PUT to update them
sometimes returns their data but without the memberships data.
Separate the form classes for creating and deleting 2015 candidacies
Make the 'information source' fields more helpful

... by using the HTML5 form validation, a placeholder and a custom error
message.
Add some more helpful text about source of changes
Create a random version identifier for each new person version

This is just so that we can reliably refer to an early revision
when rolling back a change in the future.
Split lists of candidates more helpfully

Now candidates that were standing in 2010 and are marked as standing in
2015 are only listed once.

Also, old candidates from 2010 are now split into a list of those known
*not* to be running in 2015 and those for whom we don't have any
information about 2015 yet.